var myPush = function () {
    var arr = arguments[0]
    for (let i = 0; i < arguments.length; i++) {
        arr[arr.length] = arguments[i]
    }
    console.log(arr)
    return arr.length
}

// console.log(myPush([1, 2, 3,], 'hello', 'world'))

// console.log(myPush(['上海', '北京', '宿迁'], 1, 2, 3, 4, 5))